在循环中对嵌套的ajax调用使用$ .Deferred（）

是的，使用方法

Deferred

function a() {    var def = $.Deferred();    $.ajax("http://url1").done(function(data){        var requests = [];        for (var i = 0; i < 2; i++) {  requests.push(b());        }        $.when.apply($, requests).then(function() { def.resolve(); });    });    return def.promise();}// called by a()function b() {    var def = $.Deferred(),        requests = [];    for (var i = 0; i < 2; i++) {        requests.push($.ajax("http://url2").done(function(data){ // do something console.log('b called');        });    }    $.when.apply($, requests).then(function() { def.resolve(); });    return def.promise();}function main(){    $.when(a()).done(function(){        console.log('all completed');    });}

//编辑：替换

.pipe

.done